Paul McCartney, seen here at the 2008 European MTV Awards, has wanted to do a full-length animated film for 30 years. (AP Photo/Joel Ryan)

Paul McCartney is to write an original score for a new animated film, High in the Clouds, to be produced by New Line Films.

High in the Clouds is an adaptation of a children's book written by McCartney, Geoff Dunbar and Philip Ardagh, about a squirrel's quest to find an animal sanctuary.

It is McCartney's largest involvement in an animated film since the former Beatle was part of 1968's Yellow Submarine.

McCartney composed music for 1967’s The Family Way and wrote songs such as Live and Let Die for the James Bond film of the same name and the title track of 2001’s Vanilla Sky.

The musician has committed to create a score of original songs for the animated film, the producers told Variety magazine.

The film will be directed by Rob Minkoff, who helmed The Lion King and The Forbidden Kingdom, and adapted by Caroline Thompson.

After the book was published in 2005, McCartney said it was inspired by his collaboration with animator Dunbar on the animated short Tropic Island Hum. Dunbar illustrated High in the Clouds and Ardagh co-wrote based on McCartney's ideas.

"It's been my ambition for about 30 years to do a full-length animation film," he said in 2005.

The story follows Wirral the squirrel after he is forced to leave his home by developers who bulldoze the forest. He must travel through the big city before he finds his way to safety.